Gernot oh heck yes…. The bigger, brighter and better the guide scope the more increase in reduced guiding numbers. As far as cameras go there is only the asi220mm mini, but it would need to be paired up with at least a 200mm guide scope to see much difference. It is too bad that they discontinued the asi290mm mini as it has 2.9uM pixels that are smaller than the asi120s 3.75uM pixels. That reduction in size increases the guide scope imaging resolution. The new asi220mm mini has 4uM pixels which is a step backwards for a guide scope but is a great choice for an OAG. The only better camera for a 240mm and under guide scope would be a asi178mm, but it is not a mini. It has 2.4uM pixels.
So there are not many choices available today regarding cameras, but definitely go up in size and quality of your guide scope. A 50mm or 60mm guide scope will help and if you can find a used asi290mm mini… go for it. Fyi… the asi174mm mini has huge pixels and is better suited as well with an OAG. I just started testing a mini triplet refractor 50edph with my 290mm mini as the better quality of the stars helps with the asiair centroid estimation while guiding.
